Such devices for sanding rounded edges are suitable in general for postmachining circular segments on straight, rectangular workpieces, predominantly made of wood materials, such as stair steps, furniture elements, or the like, which can thus be sanded to improve their surfaces. This is predominantly done on machines with a conveyor device for feeding the linear workpieces and with a belt sanding assembly disposed on the conveyor. Suitably shaped tools of plastic, wood, metal, or composite materials are used. Tools of metal are also known that are each made for a particular radial dimension and through which during the sanding operation compressed air flows through bores made in them, thus reducing the friction between the sanding belt and the tool.
In these methods, in order to avoid sanding errors at the beginning and end of the workpiece, a device is required that makes it possible to insert the sanding shoe at the beginning of the workpiece and to lift it at the end of the workpiece, in both cases in an exact way. Replacing these individual tools to change the profile shape, and positioning them in the belt sanding assembly, require corresponding conversion times. A substantial disadvantage of the known belt sanding devices is also that the transitions between the rounding curves and the straight surfaces adjoining them cannot be sanded cleanly, so that postmachining by hand is usually required.
In order not to have to provide a separate sanding show for every possible profile shape, a continuously variably adjustable belt sanding device is known (Austrian Patent Disclosure AT 413 958 B) with laminations displaceable relative to one another, which adapt to a profiled surface by pressing against a corresponding pattern counter to the resistance of an elastic material and can be fixed in that position by firmly clamping the laminations. However, that operation has to be done anew each time a change is made to a different rounding radius.
A profile sanding assembly (European Patent Disclosure EP 0 396 067 A2) is also known that has a tool holder, described as a tool turret, in which various tools are embodied.